000 AXNT20 KNHC 200508 TWDAT TROPICAL WEATHER DISCUSSION NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 205 AM EDT SUN AUG 20 2006 TROPICAL WEATHER DISCUSSION FOR NORTH AMERICA...CENTRAL AMERICA...THE GULF OF MEXICO...THE CARIBBEAN SEA...NORTHEASTERN SECTIONS OF SOUTH AMERICA...AND THE ATLANTIC OCEAN TO THE AFRICAN COAST FROM THE EQUATOR TO 32N. THE FOLLOWING INFORMATION IS BASED ON SATELLITE IMAGERY...WEATHER OBSERVATIONS...RADAR... AND METEOROLOGICAL ANALYSIS. BASED ON 0000 UTC SURFACE ANALYSIS AND SATELLITE IMAGERY THROUGH 0415 UTC. ...TROPICAL WAVES... TROPICAL WAVE OFF THE COAST OF W AFRICA IS ALONG 28W S OF 20N WITH A 1009 MB LOW ALONG THE WAVE NEAR 9N MOVING W 15-20 KT. LOW IS EMBEDDED WITHIN THE ITCZ AXIS WITH AN INVERTED-V CURVATURE OBSERVED ON INFRARED SATELLITE IMAGERY. CONVECTION IS WITHIN THE ITCZ AXIS. TROPICAL WAVE IS ALONG 43W/44W S OF 20N MOVING W 5-10 KT. WELL DEFINED INVERTED-V CURVATURE IS OBSERVED ON INFRARED SATELLITE IMAGERY. CONVECTION IS WITHIN THE ITCZ AXIS. TROPICAL WAVE IN THE E CARIBBEAN IS ALONG 63W/64W S OF 20N MOVING W 15 KT. UPPER RIDGE ACROSS THE E CARIBBEAN IS MASKING THE SATELLITE SIGNATURE AND ENHANCING SHOWERS/THUNDERSTORMS THAT COULD BE ASSOCIATED WITH THIS WAVE. TROPICAL WAVE IS ALONG 97W AND HAS MOVED OUT OF THE ATLC BASIN. ...THE ITCZ... ITCZ AXIS IS CENTERED ALONG 13N16W 10N25W 10N41W 8N50W 8N61W ACROSS THE N PORTION OF SOUTH AMERICA AND THE SW CARIBBEAN OVER COSTA RICA INTO THE E PACIFIC REGION. CLUSTERS OF SCATTERED MODERATE/STRONG CONVECTION ARE FROM 7N-10N E OF 15W TO THE COAST OF AFRICA...FROM 10N-15N BETWEEN 23W-26W...AND FROM 4N-11N BETWEEN 29W-35W. CLUSTERS OF SCATTERED MODERATE/ISOLATED STRONG CONVECTION ARE FROM 6N-11N BETWEEN 38W-49W. ...DISCUSSION... GULF OF MEXICO... BROAD UPPER RIDGE ANCHORED OVER E TEXAS EXTENDS OVER THE N GULF N OF 25N. THE UPPER LOW IN THE W ATLC IS PROVIDING ENOUGH DIFFLUENCE TO GENERATE CLUSTERS OF SCATTERED SHOWERS/ THUNDERSTORMS FROM THE W ATLC ACROSS THE FLORIDA PENINSULA INTO THE E GULF N OF 24N E OF 86W. AN UPPER LOW IN THE SW GULF IS CENTERED ALONG THE COAST OF MEXICO NEAR TAMPICO BUT IS EMBEDDED WITHIN DRY AIR AND NOT PRODUCING ANY SHOWER ACTIVITY. ANOTHER BROADER UPPER LOW OVER THE W CARIBBEAN IS PRODUCING ISOLATED SHOWERS S OF 24N TO OVER CUBA AND TO THE COAST OF THE YUCATAN PENINSULA E OF 92W THROUGH THE STRAITS OF FLORIDA. CARIBBEAN SEA... BROAD UPPER LOW IN THE W CARIBBEAN IS CENTERED JUST W OF JAMAICA NEAR 18N80W COVERING THE AREA N OF 14N W OF 75W TO THE YUCATAN PENINSULA. THIS IS GENERATING CLUSTERS OF SCATTERED SHOWERS/ISOLATED THUNDERSTORMS N OF 19N FROM THE WINDWARD PASSAGE TO OVER THE YUCATAN CHANNEL AND INTO THE SE GULF OF MEXICO. BROAD UPPER RIDGE EXTENDS ACROSS THE S CARIBBEAN FROM COSTA RICA/NICARAGUA ALONG 14N71W TO ACROSS THE LESSER ANTILLES NEAR 16N61W INTO THE W TROPICAL ATLC. THIS IS ADVECTING A GENEROUS AMOUNT OF TROPICAL MOISTURE ACROSS THE S CARIBBEAN AND WITH IT SCATTERED SHOWERS/ISOLATED THUNDERSTORMS OVER MOST OF THE AREA WITH SCATTERED MODERATE/ISOLATED STRONG CONVECTION FROM 12N-15N BETWEEN 78W-82W. MODERATE TRADEWINDS ARE ACROSS THE AREA. ATLANTIC OCEAN... THE UPPER LOW IN THE W ATLC IS CENTERED NEAR 28N78W COVERING THE AREA N OF 22N W OF 71W WITH AN ASSOCIATED 1012 MB LOW ALONG THE COAST OF GEORGIA JUST N OF JACKSONVILLE FLORIDA. THE UPPER LOW IS GENERATING THE SCATTERED SHOWERS/THUNDERSTORMS FROM 23N-30N W OF 78W ACROSS FLORIDA INTO THE E GULF OF MEXICO. AN UPPER LOW IS SE OF BERMUDA NEAR 29N62W GENERATING SCATTERED SHOWERS/ISOLATED THUNDERSTORMS FROM 25N-31N BETWEEN 50W-63W. AN UPPER RIDGE IS BEING INDUCED BETWEEN THESE TWO UPPER LOWS. THE UPPER RIDGE EXTENDS FROM THE E CARIBBEAN ACROSS THE LESSER ANTILLES NEAR 16N61W INTO THE W TROPICAL ATLC TO NEAR 25N46W. THE REMAINDER OF THE ATLC IS MOSTLY DOMINATED BY AN UPPER HIGH CENTERED N OF THE CAPE VERDE ISLANDS NEAR 23N22W WITH A WEAK UPPER TROUGH EXTENDING S OVER THE CANARY ISLANDS TO INLAND OVER NW AFRICA. DRY AIR REMAINS IN PLACE OVER THE E ATLC SO NO SIGNIFICANT CLOUDS OR SHOWERS ARE ASSOCIATED WITH THESE FEATURES. A SURFACE RIDGE DOMINATES THE ATLC WITH THE SURFACE HIGHS N OF THE REGION. SIGNIFICANT AMOUNTS OF AFRICA DUST CONTINUE TO MOVE OFF THE COAST OF W AFRICA TO NEAR 40W. $$ WALLACE